Dash-pot.



y n. E. BENNER,

` DASH Por. -APPLICATION FILED-APR. 24. l9-08.

Patented Aug. 24, 1915.

STATES PATENT OFFICE.

RUSSELL E. BENNER, DETROIT, MICHIGAN, ASSIGNOR T EURROUGHS ADDING.MACHINE COMPANY, OF DETROIT, MICHIGAN, Al CORPORATION OF MICHIGAN.

DASH-Por.-

v To all w/Loip it may concern Be it known thatl, RUSSELL BENNER,acitizen of the United States, residing at Detroit, in the county ofl/Vayne and State of Michigan, have invented certain new and usefulImprovements in Dash-Pots, of which the following is a specification.

My dashpot is particularly designed with reference-to adding machines ofthe type shown in Patents Nos'. 504,963 and 505,078 in whichy a handleis drawn forward after the stops corresponding to the numerals to beregistered have been set, and then released to complete the operation ofthe ma? vchine under the influence of a rather powerful spring. It isdesirable that the forward movement of the handle be made 'at a rea'sonable but. limited speed and the reverse movement'be made under lessrestriction for the most part but checked or slowed down as the handleapproaches its normal position. The dashpot which forms the subjectmattei' of the present application is pai'- tcularly adapted toaccomplish this regulation of the movement of the adding machine 'Yproper, a downwardly-projecting hollow l parts thoughobviously it maybeused in other connections where similar regulation is to be effected,and certain of its principles .-and featuresare applicable to dashpotsin general, Yas wil-l appear more fully from the following detaileddescription of a. pre-- ferred embodiment of the invention in con--nection with the drawings to which refer ence is made. f

' .part of this specification illustrate a pre- The accompanyingdrawings which form ferred form of: embodiment of the present invention,Figure-l representing a vertical section of the dash-pot with the pistonat s 40' the end of its stroke; Fig. 2 representing a similar sectionofthe dash-pot at an inter.- mediate stage in the operation of the may'chine; F ig. 3 representing a fragmentary lsectionalized elevation ofthe dash-pot, the section being at right angles to that of Figs. l and2; Fig. 4 representing a bottom plan view of the piston with thecylinder or shell .'in horizontal section; and Fig. 5 representing inperspective a plunger device detached.

In the laccompanying'drawings I have villustrated my improved dashpotdevices with lthe piston and cylinder shown With bearings forconnectiongto the proper ele- Specication of Letters Patent.

tomi and opening at both ends,v

i the tubular. extension-847b ments o f an adding machine of thecharacter.

described or other machine elements', the relative movements of whichare to be regulated thereby.

Referring now to Figs. 1 and 2 the reference numeral 847 designates thepiston proper which occupies the bore of 'the shell or cylinder 892 withsulicient clearance to provide for the latter-s sliding back and forthover the sides of ,said piston. The late ter. is formedl witlrlongitudinal ports or passage-:wijs a extending from top to botsaidports being lined with soft metal bushings 6 which preferably projectslightly above the upper surface of the piston forl a purpose herein-'-after explained. The piston is formed with a central elongatedcylindrical portion 847n open at the bottom and closed at Athe top andupwardly beyond this cylindrical portion extends a tubular part 8117* towhich the stem 802 is joined. Within the cylin- Patented Aug'.'24, 1915.

Application led April l24, 1908. Serial No. 428,999. y

drical portion 847a of the piston there slides a plunger' comprising acentral piston-like part 830, fitting the large .bore ofthe .piston'stem' or tubular part 830a forming an\oil tance in continuation of thelower stem and `grooved in' one -side as at o to provide a permanentpassageway between the interior of A of the piston and the interiorofthe cylinder 847g. A spring end against the upper end of the head ofthe cylinder 847a and at its other end against the central piston-likeportion of the plunger,

this spring thus tending to thrust the latterlnotches z' as most clearlyseen in Fig. 5. Y. O11 the' exterior of the cylinder 847a there isarranged -to slide ar sleeve 827 having atu its lower end a flange 827spaced Vfi'omvthe 889 su-rrounds the 'stem'830b bearing at one buthaving ports alining with the ports f5 ythough ot restrict* .i diameter.

The sleeve is prevented troni turningr by a pin .if projecting. upwardl)t'roin the piston (Fig. 3)

and loofzelv engaging an opening' in the llange'o'i Said f/ constitutinga ballle plate.' ft nut 847", serewinfr upon the tubular part tl-T ofthe piston provides a shoulder to'liinit the up ward niovennnt ol thesleeve of?.

'The operation ot' the dasli-pot vis aS f0llows: Normally with theovlinder S92 el'evaled or tht` piston,depressed aeeording' to whichelement is attaihed to the movable part the hollow stein Silo" is ineontaet, with the base ol" said cylinder and the spring ttfl iscompressed as shown in Fig. l. The sleeve 92T is elevated at theeonelusion of a retnin stroke ol the piston but after a period ot restof the niaehine would settle upon the piston or the bushings (i.Aitt'an'v rale downward movement oi' the #vlinder H92 or upwardniovenient ot the piston iniinediatelv rauses the said sleeve to lowerrelatively to the piston` bringing its flange H27* upon the upper endsot the bushings o. thus restrieting the passage-veais to thediaineterot' the ports lt will of course be luider-stood that thee'vlinder $92 is tharged with oil as indicated in the drawings and thatas said cylinder lowers this oil linds its `wav through .the ports r1,and f.

li'ith the lowering of the ejv'linder H92 its base. separates 'front theplunger stein Hilti and the spring S85) eventually thrusts the plungerSil() downward` so that at the end ot the vt'orward stroke the partshave assumed the relative positions illustrated `in Fig. 2. lt will beobserved that the plunger HIE() has taken up a position at the lower endol' the vlinder H47, the oil having entered freely through the'tubularstein S30 and the port li as theplunger assumes'that position underimpulse of the spring S89. lt will be understood that there is' amplespace be tween the stein 83V andthe washer dfor the oil to pass throughas said plu-nger thus moves outward or downward; Now as soon as thecylinder starts back the sleeve 827 is slid up on the eylindertl by thepressure of -foil against its flanges (j and 827'?, thelatter'-unevering-the ports a' and thus permitting acceleration in thereturn movement of parts,l both of said flanges being sepa v rated fromthe walls of thefeylinder by ample spat-es.` But `when the base'of'theeylin der Sfstrikes ,the end of thejhollow 'stein tlwla markedretardation takes place for a quantitykofoil is trapped in the chamberot the cylinder 847, and there is no escape except through the smallnotehesli. Consequently the remaining return movement ot parts isconsiderably slowed down and ain;

sleeve has an upper flange AVAILABLE copy ple time will be allowed forthe transfer or carrying operations no matter how many' are totalteplace successively. r"he downward inovenient of the Cylinder `or theupward nioveinent ot the piston isretarded only proportionally to thelimitation of the flow ot' liquid through the. piston by the ports faseoinpared to. the restriction of flow occasioned b v the size ot theports (a and such relative movement of the piston and `e vlinder is ol1course unaffected bjr the plunger within the ychamber Sli though thelatter when rel msed by the upward movement ol thel piston relative tothe .cylinder shifts as -above described. The upward movement ot' theevlinder with respect to the piston even less restrieted. because of theinoveinent ot' the ported 812i' until the bottoni of the cylindereoniesn Contact with the hollow stein 'S-l0 and tl'ie'efore up to suehpoint the relative movement of the parts is more rapid. The restrictionfor eheeking and cushioning is solely that atleeting llow .of oil outot' theiinterior plungerevlluder 84T, and the start down,- ward o't' theexterior eylinder @|92y is not rbsisted by anvvaruuni etleet within saidinl terior vlinder. The start downward of the exterior evlinder does nothave to be accompanied by flow ol' oil to said interior cylinder throughthe restricted ports formed by4 the notehes e'. 'lhe exterior cylindersimply nioves awa)` troni the notched stem and the oil flows to theinterior cji'linderifreely therealter as the spring 88H forces theplunger down. The projection ot' the bushings b above theupper surfaceot' the 'piston 84T obviates sut-,tion whieh might result as the handlestarts rearward. from Contact of the flange 32T with so extended asurface as that presented h v the upper side of said piston. it will` beunderstood that the upper flange r/ serves to prevent the oil fromshooting up through the ports when the piston 'returns heine and causinga spraying or foaming in the upperpart of the cylinder.

v`While the construction here shown is well adapted to thoroughlyIfulfil the objects primarily stated vet it is to be understood that theinvention may be Carried out otherwise and the lainis which follow` arephrased accordingly.

li'hat l claim is:

l. 1n a dashpot, the combination of a eyl-v inder and a piston. therebeing provision for the passage ollluid from one side ot' the piston tothe' other, said piston being formed with a longitudinally extendingchamber, a plunger movable in said chamber. there being eoinmunieationbetween ,said chamber vand the exterior thereof. said plunger adapt-1,150,925 .l i g carried by the piston -and portedl for the passtog'eofthe fluid, said member adapted to 'contact With the head of thecylinderD at one end kofrthe stroke Withprovisions fon' therebyrestricting the fluid flow.

3. In 'ai dash-pot the combination of ,an enrterior'rcylndel a Portedall@ Chilmbered Pis-A ton, and'a plunger in th chamber of the.

piston having a passage gepening into the same 'and into the extenorcylinder .and

adapted to contact with the head of the lat.

ter atl one end of the stroke with provisions for thereby'restrictingthe fluid flow between the chamber and theylinder.

4l. In a dash-pot the combilnation of an exterior cylind'er, a .portedand chamberetd.

piston, and a plunger in the chamber; of the piston having a passageopeninginto they same andl into Ythe exterior cylinder and adaptedtocontactJvith the head of the latter at one end of the stroke withprovisions for thereby restricting the fluid flow be -tween the chamberand the cylinder, the

, said Vpiston being cylindrically chambered;v 30, i tion fitting saidchamber and a' tubular stem plunger being spring-pre` d toward the headofthe latter.

5. In a dash-pot, the combination of an exterior cylinder; a pistontherein ported for the passage of friid in'either direction,

and a plunger comprising a lpiston-like pory projecting therefrom forcontact with the head of the cylinder, said plunger being ported toprovide for communication between the chamber and the interior of thetubular stem and 'the latter formed to cause restriction of fluid flowwhen in Contact with "the cylinder head. 1

of the plston proper, and a;tubular stem projecting outof the chamberand adapted to contact with the head of the cylinder, said plunger beingported to provide for com-v munication between the chamber andtheinterior o ,frthetubular stem and the latter formed to cause restrictionof fluid flow whenin contact with the cylinder head.

f7. In a dash-pot, the combination of an exterior cylinder; la pistonthereinported [for the-passage of fluid in either direction,

said-piston being .cylindrically chamberedy' a plunger comprising apiston-like portion fitting said chamber and a tubular stem pr'ojectingtherefrom for contact with the head of the cylinder, said plunger beingported to provide for communication between the chamber and th'einterior of the tubular stem and tha latter 4formed to .causerestriction of fluid flow when in contact with the .cylinder l head;anda spring forcing the plunger outwardly.

8. In a dash-pot, the combination of an exterior cylinder; l a pistontherein 'ported for the passage of fluid in either direction, said.piston being cylindrically chambered and bored; a plunger comprising acentral piston-like'portionfitting the said chamber, f a; guiding stemengaging the bore of the p1ston proper, and a tubular stem projecttactwith .the .heady of the cylinder, said plunger being ported .to providefor com formed to cause restriction of fluidl flow when in .contact withthe cylinder head; and a spring surrounding Vthe, guiding stem of theplunger and tending to force the latter `outwardly.

9. In a dash-pot the combination with vcylinder and piston, of a slidingtubular member carried by -thejpiston and ported forv the passage -ofthe fluid, .said tubular member adapted to contact with the head of thecylinder at .one end of the A stroke and -ing out of the chamber andadapted to conj munication between the chamber ,and the interior o fthel tubular stem and the latter` being notched to then permitrestricted fluid flow.

L 10.111 a dash-pot, the' combination of 'an I exterior cylinder; a'piston therein ported' for the'passage of fluid in either' direction,

said piston being cylindrically chambered; and a plunger comprising apiston-like p ortion fitting said chamber and-Ia, tubular' stemprojecting therefrom for contact w-iththe -head of the cylinder, saidplunger' being ported to provide for communication bemit restrictedfluid flow when in contact 'with the cylinder head.

11. In' .a dash#pot, the' combination of'an tween the chamber and theinterior of the i tubular stem and the latter notched 'to per.-

exterior cylinder ;l a Apiston therein ported.

for the passage of fluid in either. direction, said piston beingcylindrically chambered;

a plunger comprismg a piston-like portionA fitting said chamber and atubular stem projeclting therefrom for Contact with the head of thecylinder, ,said plunger being ported to provide for communicationbetween the chamber and the interior of the tubular stem and the latternotched to permit restricted fluid flowI when in Ycontact, with thecylinder head; anda spring forcing the plunger outwardly.

l2.` In Va dash-pot, the combination of an exterior cylinder, pistontherein ported forA Afluid flow in either directiona'nd a sliding,

sleeve on the'piston flanged to cover the port or ports of thelatterfand itself restrictedly ported, said sleeve having 'a secondflange extending over the port ofthe firstmentioned flange. l

13. In a dashpot, the combination of an exterior cylinder, apiston-therein ported for forming a chamber therewith, there being',

fluid flow in either direction and having a raised portion encirclingthe port, and a slidingr closure piece for the piston port adaptedtoseat against said raised portion while separated from the surroundingsur 'face of the piston, said closure itself beingr restrictedly portedin alinement therewith.

14. In a dash-pot the 1combination of an exterior cylinder, a ported andchambered piston, a plunger in the chamber of the piston having apassage openingr into the same and into the exterior cylinder andadapted to contact with thehead of the latter at one end of the strokewith provisions vfor thereby restrictingthe fluid flow between thechamber and the cylinder, and a sliding closure piece for the pistonport itself restrictedly ported in-alinement therewith;

15. In an appliance of the character described, the. combination ofmeans Jfor uniformly retarding the stroke in one direction, means forApermitting,r acceleration in the opposite direction throughout thegreater portion of theistroke, and luid operated means ior retarding andcushioningr the latter stroke at its end, while elin'iinating suction orIvacuum resistance lat the lconnnencement oi the lirst-mentioned stroke.A

1G. In'a .dash-pot, a cylinder and piston, the latter provided With arelatively mov?, able membermounted in the piston and provision for thepassage of liquid to and from said chamber and means for arresting. themovement of said movable member during the latter portion of themovement-of the piston. I-

17. In a dashfpot, a cylinder and piston provided with passages foriiuid from one side ,of the piston'ut'o the other, means for throttlingthe lowofliquid in one direction only, a chamber in the piston, avplunger movable in the chamber, means for arresting the motion of theplunger' as the piston nears the end of its stroke there being a passagefrom the chamber to the exterior o f the piston andprovision forthrottling the passage` when the plunger moves inward in the chamber.

18. In a dashpot, a cylinder and piston, the latter provided with arelatively movable member mounted in the piston and forming achamber'therewith and having'a port therein for the passage of liquid tosaid chamber, and means for arresting the movement of said movablemember during the latter portion of the movement of thepiston anddecreasing the fiow of fluid through said port.. f v

19. In a dashpot, the lcombination with lthe cylinder andpiston, of anaxially slidfing member mounted in and closingr a chamber in said pistonand having a passage f -therethrough, said member adapted to come "incontact with the head of the cylinder and l.thereby partially close saidpassage.

RUSSELL E. BENNER.v

Witnesses J. VINCENT, Il. S. MIELERT.

